In modern agricultural industries, accuracy is essential. Accurate record keeping, automated mapping, and precision farming techniques have all become crucial factors in the challenge to improve overall crops yields and comply with the ever increasing number of environmental regulations. The accurate application of herbicides, pesticides and fertilizers is an essential component of modern precision farming methodologies. Whether such applications are performed by aerial or terrestrial techniques, advanced tools that provide highly accurate navigation and guidance information for operators have become a requirement.
The transfer of global positioning system (GPS) technologies to civilian industry has greatly assisted in meeting the challenges presented by today's precision agricultural needs. Using GPS systems, accurate and highly reliable satellite-based positioning information, which typically achieves less than one meter accuracy by utilizing differential GPS position corrections transmitted from fixed base stations, is provided to operators, for example though moving map displays. Such information allows for precise navigation and guidance. Systems utilizing GPS technology have been used in the past to assist in the aerial and terrestrial application of fertilizers, herbicides and pesticides, etc. However, such systems have generally been limited in their capabilities.
For example, as shown in FIG. 1A, GPS guidance systems which allow operators to follow essentially parallel line spraying routes across a field have been used. For given field, an operator in a sprayer rig 10 may begin a spraying pattern along an initial line 12. At the end of the field, or at some point prior to the end of the field, the operator generally maneuvers the sprayer rig 10 onto a return path 14. The return path 14 is essentially parallel to the initial path 12 and is separated from the initial path 12 by distance corresponding to the width of the spray pattern. An alternative spraying pattern is shown in FIG. 1B. This spraying pattern resembles a race track pattern and again provides essentially parallel line spraying patterns.
Spraying patterns such as those shown in FIGS. 1A and 1B are useful for aerial applications and for terrestrial applications involving row crops. However, such spraying patterns are not well suited for terrestrial spraying applications involving open field crops, for example, wheat, barley, etc. Typically, such crops are grown over terrain of varying contours and often in fields which present obstacles to straight line spraying patterns. What is needed, therefore, is a precision farming guidance and/or control system for terrestrial spraying applications which may be used in an open field crop environment.